Can't waste any more time on this so;
38a Linguistic study an evil-sounding duty (6)
S?N?A?
SInbad? If so, where is the definition?
46d Illiterate woman was in a dive (7)
S?E?E??
shefell or something?
55a Not so happy in second run, losing the lead (6)
S?D?E?
Sadden? Can't parse
finally;
56a Begin to fail, but second covering ground (4,4)
?E?R ?H??
For the parses we are about to receive, please make us truly grateful!